Ted Jackson/The Times-PicayuneA National Guard helicopter drops a sand bag into a break in the beach just west of Grand Isle on Monday in an effort to protect delicate marshlands from the oil slick moving westward from the Deepwater Horizon leak in the Gulf of Mexico.

As for the passes that tie the Gulf to the inland marshes of Jefferson and Plaquemines parishes, officials say boom alone stretched across the coastal openings likely will not remain intact because of waves, wind and current.

Instead, Grand Isle Mayor David Camardelle said officials plan to lay hardened boom in a "J" configuration in these passes, with hopes that the oil moving toward the west will be deflected back into the Gulf.

"The best we can do is keep this oil out of these interior wetlands," Gov. Bobby Jindal said during a stop in Port Fourchon on Monday, after taking a tour of two Army National Guard operations are underway.

In an operation reminiscent of efforts to plug levee breaches in New Orleans after Hurricane Katrina, National Guard UH-60 Blackhawk crews from Hammond were flying bags of sand weighing as much as 4,500 pounds to a coastal breach at Bayou Thunder at the Jefferson-Lafourche line. The air crews dropped 26 bags there Monday and will continue the task at four other sites along Lafourche's coast in the coming days.

Meanwhile, at Elmer's Island just west of Grand Isle, Army National Guard engineers are building a 700-foot berm to fill a gap in the barrier island through which oil could eventually pass.

"The barrier islands are a critical part of our defense," Jindal said.

At the nearby Chenier Pass, Camardelle said he hopes to string absorbent boom along the Louisiana 1 bridge to Grand Isle.

But the problem along the coast here is no different from elsewhere: A shortage of boom. Grand Isle has asked for 55,000 feet of hardened boom, but has gotten only 26,500 feet, Jindal said.

U.S. Sen. David Vitter said he is seeing "an enormous discrepancy" in the boom sent to Louisiana compared with what other states threatened by the oil have gotten.

"Louisiana is not getting adequate supplies in terms of what's out there," Vitter said.

So far, Camardelle said, Grand Isle has not been touched by oil and is hoping that the Mississippi River's current rolling out of Southwest Pass will push the sheen and sludge out of a coastal cove from the river's delta to Grand Isle.

However, the specter of it passing to the south of the island already has had its effects, including on the commercial fisheries. Noting the economic impact fisheries have in Grand Isle, 12 million pounds of shrimp were sold out of the barrier island last year, Camardelle said.

Several of the 25 annual fishing rodeos held at Grand Isle have been canceled, he said. Camardelle refrained from thinking what the oil could do to "the grand-daddy of them all," the Grand Isle International Tarpon Rodeo in July.

Still, he said, he finds himself countering erroneous reports that oil has hit Grand Isle.